7kfv | pdb_00007kfv

Structural basis for a germline-biased antibody response to SARS-CoV-2 (RBD:C1A-B12 Fab)

spinqualitylabelsall models 7kfv, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7kfv is a 9 chain structure with sequence from Homo sapiens and Severe acute respiratory syndrome coronavirus 2. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.102Å Ligands: NAG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function SPIKE_SARS2 attaches the virion to the cell membrane by interacting with host receptor, initiating the infection (By similarity). Binding to human ACE2 receptor and internalization of the virus into the endosomes of the host cell induces conformational changes in the Spike glycoprotein (PubMed:32142651, PubMed:32075877, PubMed:32155444). Uses also human TMPRSS2 for priming in human lung cells which is an essential step for viral entry (PubMed:32142651). Proteolysis by cathepsin CTSL may unmask the fusion peptide of S2 and activate membranes fusion within endosomes.[HAMAP-Rule:MF_04099] mediates fusion of the virion and cellular membranes by acting as a class I viral fusion protein. Under the current model, the protein has at least three conformational states: pre-fusion native state, pre-hairpin intermediate state, and post-fusion hairpin state. During viral and target cell membrane fusion, the coiled coil regions (heptad repeats) assume a trimer-of-hairpins structure, positioning the fusion peptide in close proximity to the C-terminal region of the ectodomain. The formation of this structure appears to drive apposition and subsequent fusion of viral and target cell membranes.[HAMAP-Rule:MF_04099] Acts as a viral fusion peptide which is unmasked following S2 cleavage occurring upon virus endocytosis.[HAMAP-Rule:MF_04099] Publication Abstract from PubMed The SARS-CoV-2 viral spike (S) protein mediates attachment and entry into host cells and is a major target of vaccine and drug design. Potent SARS-CoV-2 neutralizing antibodies derived from closely related antibody heavy chain genes (IGHV3-53 or 3-66) have been isolated from multiple COVID-19 convalescent individuals. These usually contain minimal somatic mutations and bind the S receptor-binding domain (RBD) to interfere with attachment to the cellular receptor angiotensin-converting enzyme 2 (ACE2). We used antigen-specific single B cell sorting to isolate S-reactive monoclonal antibodies from the blood of a COVID-19 convalescent individual. The seven most potent neutralizing antibodies were somatic variants of the same IGHV3-53-derived antibody and bind the RBD with varying affinity. We report X-ray crystal structures of four Fab variants bound to the RBD and use the structures to explain the basis for changes in RBD affinity. We show that a germline revertant antibody binds tightly to the SARS-CoV-2 RBD and neutralizes virus, and that gains in affinity for the RBD do not necessarily correlate with increased neutralization potency, suggesting that somatic mutation is not required to exert robust antiviral effect. Our studies clarify the molecular basis for a heavily germline-biased human antibody response to SARS-CoV-2. Molecular basis for a germline-biased neutralizing antibody response to SARS-CoV-2.,Clark SA, Clark LE, Pan J, Coscia A, McKay LGA, Shankar S, Johnson RI, Griffiths A, Abraham J bioRxiv. 2020 Nov 13:2020.11.13.381533. doi: 10.1101/2020.11.13.381533. Preprint. PMID:33200128 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Antibody 3D structures

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